Cylinder lock



Apr-i123, 1940. R T NE 9 2,197,952

CYLINDER LOCK Filed Oct. 24, 1935 INVENTOR. Poem-e 5670/1/4- BY 6 MW+ ATTORNEYS.

Patented Apr. 23, 1940 UNITED STATES PATENT OFFICE.

CYLINDERQLOCK Porter E. Stone, Detroit. Mich. Application October 24, 1935; Serial No. 46,456

1 Claim.

This invention relates to a pin tumbler cylinder lock.

It is an object of this invention to produce a pin tumbler cylinder lock which is thief-proof in that it is practically impossible,-or at least exceedingly diificult, to pick.

As is well known, cylinder locks are being extensively used on automobiles. these cylinder locks becomes inoperative, the

owner drives his car to a garage for repair. Heretofore it has been necessary for the garage man to do one of two things in order to repair the pin tumbler cylinder lock. Either he must have on hand a duplicate of the identical coded cylinder lock which has become inoperative, or else he must send the code number of this cylinder lock to the factory where a new cylinder lock is set up identical with the one which has become inoperative.

It is an object of this invention to obviate the need for the repair man keeping on hand a duplicate of any coded cylinder lockas well as the need for sending tothe factory for a duplicate. This objecthas been achieved by producing a pin tumbler type of cylinder lock which can be coded by the ordinary garage man or repair man at the place of repair. Such a pin tumbler cylinder lock requires only that the garage man maintain on hand one or more of what may be termed blank or uncoded cylinder locks, any one of which can be readily coded by the repair man and substituted for any coded cylinder lock which has become inoperative.

In the drawing:

Fig. l is a longitudinal section through the pin tumbler cylinder lock which is the subject of this invention.

Fig. 2 is a section along the line 2-2 of Fig. 1. Fig. 3 is a plan view partly broken away along the lines 33 of Fig. 2 with the spring cover, and

the pins in two cylinders omitted.

Fig. 4 is the lock casing removed showing the self-retaining pins.

Fig. 5 is a section of the tumbler cylinder in- 5 verted to show that the tumblers cannot fall out of the cylinder.

Fig. 6 shows a suitably coded key positioned in the tumbler cylinder with the tumblers coded to this given key. so Referring more particularly to the drawing there is shown a lock casing I which is bored as at 5 or otherwise formed to receive a cylinder 2. The cylinder 2 is rotatably mounted in the bore 5. The cylinder is provided with a keyway 3 55 and an eccentric pin 4 for operating any mech-l' When one of anism with which the cylinder lock may be associated.

The cylinder 2 is provided with a plurality of openings 6 extending from the outer surface of the cylinder radially inwardly into communica- 5 tion with the keyway 3. Each opening 6 is provided with a driving pin 1. Inasmuch as the pins 1 are cylindrical therefore the openings 6 are cylindrical. Each cylindrical opening 6 is provided with diametrically opposed groovesfl ll) in its side walls. The guideways 8 are arranged to receive the lugs 9 formed homogeneously with, or otherwise fixed to, each pin 1. Although only one lug 9 and groove 8 is necessary two of such lugs and grooves are preferable for each driving pin 1. The inner or key engaging end ID of each driving pin is conical with the apex of the cone rounded off. Each driving pin is identical with the others- The lugs 9 on each pin are positioned exactly the same distance from the key 20 engaging end ID of the driving pin.

The pins 1 are arranged to be self-retaining in the cylinder 2. For this purpose the outer ends of the grooves 8 are closed or obstructed so that the lugs 9 cannot slide out of the guide-.25 ways 8. --This obstruction may be very easily obtained by reforming or peening the metal of the cylinder over the outer ends of the guideways as at H. Thus the stop H in conjunction with the lug 9 operating in the groove 8 perma- 3O nentlyretains the driving pins 1 within the bore 6 in the cylinder 2.-

The casing l is also provided with the usual openings lz for receiving the tumbler pins 13.- Inasmuch as the tumbler pins l3 are cylindrical 35 therefore the openings l2 are cylindrical. Each opening 12 is provided with a groove l4 terminating short of the bore 5. Each pin I3 is provided with a pair of lugs l5 which travel in the grooves I4. The lugs l5 are positioned the same- 40 distance from the end of each pin. Each pin I3 is backed up by a'coil spring H5 in the outer end of the openings [2 which are closed by a plate l1 seated in a recess IS. The plate I! may be retained in the recess H! by peening over the edges of the recess as at l9. v

It will be seen, especially from Fig. 4, that the lugs IS in conjunction with the grooves M which have both ends closed serve to permanently retain the tumbler pins l3 within the openings I2 in the casing I.

In Fig. 6 there is shown a key 20 which is provided with a plurality of bits 2| and intervening valleys 22 which determine the code of this lock. In the assembly of the lock the pins 5 l3 are assembled in the casing I, as above described, before the cylinder 2 is inserted therein. As initially assembled in the cylinder 2 the driving pins 7 are all of equal length. The driving pins 1 are mounted in self-retaining relation in the cylinder 2. The key 20 is then inserted in the way 3. As shown in Fig. 6, the driving pins 1 will be projected different distances beyond the outer surface or circumference of the cylinder 2. The differences in the amount of projection of the several tumblers is indicated in the dotted lines, Fig. 6. After the key has been inserted in the way 3 any suitable instrument, such as a file, may be used to grind off the projecting end portions (shown in the dotted lines, Fig. 6) of the several driving pins I so that the end portions are all flush with the circumference of the cylinder 2. This will now make the driving pins I all various lengths to conform with the code of the key 20.

It will be seen from the above that all the garage man need keep on hand are these blank cylinders such as 2 having driving pins I all of the same length. Whenever any lock becomes inoperative, all he need do is insert the key of.

this lock, regardless of its code, into the way 3 of a cylinder 2 and then file the projecting ends of the pins 1 down so that the ends of the pins will be flush with the circumference or surface of the cylinder 2. This will result in this blank cylinder and driving pins being coded to the key.

The several methods which are pursued in picking a lock will not be outlined here. However, it need only be mentioned that it is essential in picking a pin tumbler lock of the type heretofore known to insert an instrument in the way 3 and project the pins, such as 1 and I3, upwardly against the coil spring l6 until the springs are collapsed and the tumblers have reached the limit of their outward projection. This seems to be the first essential step in picking a lock so that the picker can get his initial reading of the respective lengths of the several tumblers. However, with the instant lock provided with the lugs 9 and stops l I, when the picker follows this practice the lugs 9 of each driving pin engage the respective stops II and consequently all of the rotation of said members, a keyway in the said cylinder member communicating with the said openings and adapted to receive a key, a reciprocable tumbler pin for each opening in the said casing member, a coil spring between the bottom of each opening and the tumbler pin for projecting the tumbler pin into the opening in the said cylinder member to lock the said members against rotation, a reciprocable driving pin for each opening in the cylinder member extending into the keyway and arranged to engage a corresponding tumbler pin whereby upon insertion of a key in the keyway the driving pins retract the tumbler pins flush with the outer surface of the cylinder to permit rotation of the cylinder within the casing, a groove in the side wall of each opening in the cylinder, the grooves being all of equal length and closed at their outer ends, a projection carried by each pin a predetermined distance from the key engaging end of the pin and extending into, and arranged to travel along, the said groove, the said projections on the driving pins and closed ends of the grooves in the sidewalls of the openings in said cylinder being so positioned that outward movement of the driving pin will be arrested before the tumbler pin completely collapses the coil spring, the said projections on the said driving pins being positioned equal distances from the ends of the pins and cooperating with the outer closed end of the said guideway groove whereby when the driving pins are fully projected the'key engaging ends of said pins are aligned.

PORTER E. STONE. 

